A packaged semiconductor device has a plurality of leads, that is, electrodes projected from a package body. The semiconductor device of this type is electrically tested by using an electrical connecting apparatus called socket. Such electrical connecting apparatus are described in Patent Documents 1 and 2.
[Patent Document 1] Japanese Patent Appln. Public Disclosure No. 11-31566 Official Gazette
[Patent Document 2] Japanese Patent Appln. Public Disclosure No. 2003-297506 Official Gazette
Each of the electrical connecting apparatus described in Patent Documents 1 and 2 comprises a plurality of probes having a curved portion, a cover on which the probes are arranged in parallel, and a stick-like needle presser arranged in a cover so as to extend in the arranging direction of the probes.
The cover is attached to a base plate such as a wiring base plate by means of a plurality of screw members. The probes are pressed at the outer surfaces of the curved portions against a conductive portion of the base plate by the needle presser in a state that the cover is attached to the base plate.
The device under test, whose electrodes are pressed against the tips (needle tips) of the probes, is electrically connected to the electrodes of the base plate by the probes.
In such an electrical correcting apparatus as above, however, the outer surfaces of the curved portions of the probes are only pressed against the conductive portions of the base plate with the cover attached to the base plate, the probes tend to fall from the cover in a state before the cover is attached to the base plate, thus making an assembling work troublesome.